Ala. Code § 23-1-94

Nothing in this article shall be construed to authorize the county commissions of the several counties to establish, promulgate, or enforce any rules, regulations, or laws which may be in conflict with a local or special law providing for the working, maintenance, change, discontinuance, or improvement of the public roads, bridges, or ferries of such county now in force or which may hereafter be enacted, except in cases where the State Department of Transportation has jurisdiction over such highways.